This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Previously it was shown that when the nucleus of interphase cells were irradiated with the NIR laser a darkening occured at the area of laser exposure and that DNA damage repair factors were observed to localize to the area of damage. Currently we are irradiating chromosomes in vivo and have observed a black dot forming at the site of exposure. Immunofluorescence staining will show wether the black dot coincides with the recruitment of DNA damage recognition and repair factors.